feat: Ability to save a credential - createCredential

[Tkko]

Feature Request: Add Support for createCredential Method in Android Credential Manager

Objective:

Implement the createCredential method to allow users to securely save their credentials (username and password, etc) to the Android Credential Manager through the SmartAuth Flutter package.

Tasks:

1. Research Android Credential Manager API:

   • Review the createCredential method in the Android Credential Manager documentation.
   • Understand the required permissions and configurations to save credentials.

2. Native Android Implementation:

   • Implement the createCredential functionality in Android using the Credential Manager API.

3. Flutter Integration:

   • Create a dedicated Dart method to call the native Android implementation via Pigeon generated API.
   • Example API:

     Future<SmartAuthResult> createCredential(params);

4. Handle Edge Cases:

   • Handle scenarios such as:
     • Invalid or empty credentials.
     • Permissions denied by the user.
     • System-level errors or unsupported devices.
   • Provide meaningful error messages for these cases.

5. Update Documentation:

   • Add a section to the SmartAuth documentation explaining:
     • How to use createCredential.
     • The purpose and benefits of saving credentials.
     • Any Android-specific requirements, such as API level.
   • Provide code examples for integration.

6. Enhance the Sample App:

   • Add functionality to the sample app to demonstrate saving credentials using createCredential.
   • Include clear UI prompts and interactions for testing.